This invention relates to centerless grinding machines. More particularly to an outer diameter (O.D.) grinding machine for grinding cylindrical workpieces comprising diamond. In some applications a grinding machine is used to shape and finish a diamond workpiece after being sintered in a high temperature high pressure press. There are a number of problems that arise during grinding that slow production and may compromise the quality of the workpieces. Precision grinding is often difficult to achieve requiring that the workpieces run through a grinding process multiple times. The workpieces are often run across a grinding wheel and measured after each pass; usually resulting in recalibrating the grinding machine and running the piece through the machine again to minimize the blemishes created during the previous passes.
Such problems have been addressed in U.S. Pat. No. 6,077,146, to Sato, et al., which is herein incorporated by reference for all that it contains. The '146 patent discloses a taper correcting apparatus for a grinding machine, a workpiece supporting means for supporting a workpiece in parallel with the grinding wheel, and a cutting and feeding device which moves back and forth a cylindrical grinding wheel with respect to the workpiece. The patent also discloses a pair of grinding wheel bearing pedestals which rotatably support ends of the grinding wheel spindle via bearings with respect to the wheel slide, respectively. A first grinding wheel bearing pedestal support which is fixed to the wheel bearing pedestal support with is fixed to the wheel slide, and which clampingly supports one of the grinding wheel bearing pedestals is disclosed along with a second grinding wheel bearing pedestal support which is attached so as to be rotatable about a round shaft, and which clampingly supports another one of the grinding wheel bearing pedestals, the round shaft being attached below the grinding wheel spindle to the wheel slide in parallel with the center line of the workpiece. The invention also discloses a pressuring device which presses the second grinding wheel bearing pedestal support to rotate the second grinding wheel bearing pedestal support about the round shaft, thereby changing a distance between a center of the grinding wheel spindle and a center of the workpiece. Means for controlling a pressing amount of the pressuring device so that parallelism between the center line of the workpiece and a center line of the grinding wheel spindle is corrected is disclosed.